just bought a few of these https://www.ebay.com/itm/263413024138/ are they sold for so low because they exceeded their operating life or they likely damaged parts?

is it likely they work will work close to their spec?

 

I would guess that they are fine. But that's only a guess.

They have been used......and priced as such. I would bet they're still in spec. But I am a terrible gambler.

 

I would think they will last "forever" unless damaged. It will be pretty easy to test.
Measure the capacitance and if you have a high voltage Megga, run them up to 10KV or so to check for leakage.
A quick search could not locate any new parts of that type number but no doubt they are available somewhere. Bu the Ebay second hand caps should be ok I reckon.

 

2500pf 20KV !!! This is the sort of capacitor you can build yourself for a fraction of the price ..

Wax paper and aluminium foil ....Wax paper breaks down at 40Kv /mm so 1mm thick is ample (polythene is also good )

2500pf is so small you wouldn't need much of an area for the 'plates'.... Anyone know how much???

EDIT ... here we are ....

e = 17.5 x 10 minus 12 ..............C = 2500 x 10 minus 12

2500 = 17.5 x A/ d ................. d = 1 mm ....

So 2.5/17.5 = A ............. Area of plates is around 0.14 of a square meter ... very easy to make .

 

Hello,

Here you will find more capacitors of that kind here:
http://hvstuff.com/high-voltage-capacitors/ceramic/doorknob

Bertus

 

Interesting design ....